Hi danny to change ring gear remove side cover,remove hyd pump assy from transmission,take off all pipes from transmission,remove starter motor,undo the 4 bolts that hold trans to bell housing and lift trans out,its not too heavy and you should be able to remove on your own.
Undo bottom+side engine mountings on bellhousing,support engine and remove bellhousing.
Remove flywheel and fit new ring gear,their is a ring gear/starter modification available from Linde.Then rebuild in reverse order.
The cam belt should be changed at 3000hrs,it is recommended that the belt,idler,adjuster and rollers are replaced at the same time.
Hope this helps
herald.